Phase lock loop synchronization circuits are often used to synchronize related signals. For example, such related signals frequently exist in video graphic display circuits wherein horizontal sync pulses must be in phase with a higher frequency such as a "dot-frequency" on which the generation of individual dots making up a video graphic display are based. Such phase lock loop circuits require that the two frequencies be harmonically related, which is not always possible. In lieu of such phase lock loop circuits, it is also known to gate a crystal oscillator by reference signal pulses, however, the precision of such gating has associated with it timing errors of up to .+-. one period of the crystal oscillator frequency. Also, while RC-type oscillators may be reliably keyed by reference signals, such oscillators typically exhibit frequency instability and inaccuracies, particularly immediately after first being activated. As one primary use for a synchronization circuit would be to precisely key an extremely stable oscillator, thus, providing a very precise phase and frequency source for use in raster scanned video graphic displays, without the need for phase lock loop clocking or a harmonic relationship existing between the oscillator frequency and that of the reference signal, such previously known circuits have proven unsatisfactory.